Climate Change and your Garden
Catherine Tapner
Have you noticed extended periods of dry weather, interspersed by sudden deluges of rain? Feeling a little hot lately? Well imagine what it is like for your plants, outside all day, heat stressed and thirsty, and then bombarded with water. There is no doubt the climate is changing, regardless of arguments of how and why. We have to learn to adapt. The year 2005 was one of the driest years on record yet, in 2004, we were drenched in rain. Remember the July flood? The monthly total precipitation in 2005 was, at times, less than 60 percent of the average summer month. Patterns have shown long dry periods with about two rain events per month. So how gardeners cope?
One of the most important things is mulching. Good mulch of about 2 inches around the plants protects the soil from losing moisture. Loam or compost also helps protect the plants from drying out and provides adequate drainage during rain events. Fertilize plants with organic fertilizer which helps hold water. Don't use too much nitrogen as this can cause the plants to grow too fast requiring more moisture.
Being proactive rather than reactive, reduces stress on plants and helps prevent insect infestation and disease. Xeriscaping, planting native plants or plants less susceptible to drought are a really good idea. Garden centres and the Peterborough Ecology garden are great resources for this information. Rock gardens with mulch and small dry riverbeds to direct heavy rain away from your plants will help protect the plants and prevent erosion. Pottery containers that are glazed and plastic pots hold moisture longer than unglazed clay ones.
Don’t cut your grass shorter than 3 inches, as longer grass reduces moisture loss. Grass that is allowed to grow longer develops a deeper root system, where there is less moisture loss. Leave grass clippings on the ground to provide some mulch, this will add nutrients and reduce moisture loss. Remember just because your grass turns brown does not mean that it is dying, it is just taking a little rest, (dormancy) until the weather moderates a bit. If you are seeding your grass, try seeding with fine fescues and a little perennial rye, these are more drought tolerant.
Plant vegetables that prefer their feet wet like celery in a gully, and plant those that like it dryer up on the top of mounded rows. Shelter plants that don't like the hot sun closer to taller plants, to provide some shade. Don't locate them too close to cause the roots to compete for moisture. High humidity can encourage mildew if there is not enough air circulation. Last summer, peppers and cabbages did not start producing until the moderate weather in September. When summers are hot, these plants may do better in dappled light. If your area is open and subject to high winds, plant a wind buffer. Cedar hedges are great for this and can also provide shade.
Rain barrels are a must. You can make a device that can redirect flow from the downspout to the rain barrel, and over to another rain barrel when the first one gets full during a heavy rain. Solar pumps can be purchased for your rain barrels that will pump the water into your garden. Use soaker hoses for your garden. You can get away with watering only once a week if you have the right type of soil, mulch, and use heat tolerant plants. Here you would water deeply, about 6 inches for annuals and about 12 inches for shrubs and some perennials. Never water in the heat of the day, the leaves will burn and the water evaporates too quickly.
The temperatures in fall have also been warmer, reducing chances for plants to develop cold hardiness and then, a lack of insulating snowfall for protection from frost. Mulch well with leaves to help insulate your plants throughout the winter, chances are you are not going to get enough snow to do this for you. We have also had longer growing seasons due to climate change; this could be a good thing for some plants. My peppers almost made it last year.
Plan ahead for your garden. Listen to Environment Canada's predictions for the summer or buy an Almanac. Farmers have learned to read the weather, and they have done this for centuries. Keep regular water level measurements and records for your wells they can help determine if your well is been affected by dry weather. There are fact sheets prepared by the Ministry of Agriculture, food and Rural affairs on "Preparing for irrigation during water shortages" and "Dealing with water shortages for Private well owners" Peterborough Green-up also has great packages called "Well Aware".
Researchers are developing new varieties, types, cultivars and hybrids to provide plants better suited to temperature, moisture and other conditions that are affected by climate change i.e. heat, drought, frost and flooding. Timing of your operations, like planting, spraying, or harvesting can now be based on weather predictions spread over weeks, or based on seasonal forecasts. The Canadian Climate Impacts and adaptation Research Network has some interesting articles at their website www.cciarn.ca.
You can't run from the wind, make it rain or stop the rain, but you can monitor and plan ahead. Remember the old Girl Guide motto "Be prepared".